Question

You wish to measure the speed of vehicles on an interstate highway in which you are driving. You adjust your travel speed until the number of vehicles passing you equals the number of vehicles you are passing. Have you found the mean or median speed of vehicles on the interstate highway?

Answer 1

In the described situation, you're finding an approximation of the median speed of the vehicles on the highway, not the mean. This is because your speed would represent the middle value in a set of speeds.

Step-by-step explanation:

Under the scenario you've outlined, the speed you've adjusted to is more akin to the median speed. The reason being that when the number of cars you pass is equal to the number of cars that pass you, your speed would be the middle value in the set of all speeds, which is the definition of median. Mean, on the other hand, would require you to add all the observed speeds together and divide by the number of observations, which isn't feasible while simply observing the traffic around you. Remember, though, this is a gross approximation; actual traffic studies use much more precise methodology.

Learn more about Speed Measurement